1. Field of the Invention
The present invention relates to a light source module. More particularly, the present invention relates to a light source module using a semiconductor light source.
2. Description of Related Art
Referring to FIG. 1A, a conventional projection apparatus 100 includes a light source module 110, a polarization beam splitter 120, a liquid crystal on silicon panel (LCOS panel) 130, and a projection lens 140. The light source module 110 is used to provide an illumination beam 112, and the polarization beam splitter 120 is disposed on a transmission path of the illumination beam 112. The polarization beam splitter 120 has a beam splitting surface 122. A P-polarization light 112p of the illumination beam 112 passes through the beam splitting surface 122 and an S-polarization light 112s of the illumination beam 112 is reflected by the beam splitting surface 122 to the LCOS panel 130. The LCOS panel 130 is used to convert the S-polarization light 112s into an image beam 112′ with the P-polarization, and the image beam 112′ is reflected by the LCOS panel 130 to the projection lens 140. The projection lens 140 is used to project the image beam 112′ onto a screen (not shown), so as to display an image on the screen.
The light source module 110 includes an integration rod 114 and a light source assembly 116. The light source assembly 116 includes a plurality of light emitting diodes (LEDs) 116a. The integration rode 114 is used to uniform the illumination beam 112 emitted by the LEDs 116a, such that the brightness of the image projected by the protection apparatus 100 is relatively uniform.
Referring to FIG. 1B, a diverging angle θ of the illumination beam 112 provided by the LED 116a is relatively large, and the integration rod 114 does not have a light converging function, so the diverging angle of the illumination beam 112 after passing through the integration rod 114 may not be reduced. In other words, the diverging angle of the illumination beam 112 provided by the conventional light source module 110 is relatively large, so the light utilization efficiency is relatively low, and the brightness of the image projected by the protection apparatus 100 is reduced.